Protein-Calorie Malnutrition: A Host Determinant for Pneumocystis carinii Infection

The role of protein-calorie malnutrition in Pneumocystis carinii pneumonitis was explored with comparative studies in man and animals. Collective data from 225 cases of P carinii pneumonitis revealed mean body weights and serum protein values that were below normal. In matched comparison of 44 children with cancer and P carinii pneumonitis, serum albumin values and body weights were significantly lower than those of 44 patients with malignant neoplasms of the same type, duration, and therapy, but who did not have pneumonitis. Of 39 South African children who died with kwashiorkor, three (7.7%) were found to be infested with P carinii, whereas no organisms were found in the lungs of 21 well-nourished and geographically matched children. In Sprague-Dawley rats fed a 23% protein diet for normal growth, none of 15 acquired P carinii; whereas, 13 of 15 fed a protein-free diet died infested with P carinii.